We successfully brought nanoFACS, a method for analyzing and sorting naonoscale particles, to NIH, by modifying the Influx flow cytometer in a NCI/CCR core FACS facility in Building 10. This now allows us to analyze and sort exosomes and microparticles as small as approximately 100nm. We have developed and tested numerous modifications of the technique and instrument configuration to improve the detection limits, and hope to have methods in place within the next 6 months to routinely analyze and sort particles as small as 40nm (which would span the full range of biologically significant exosome sizes). Over the next year, we will continue 1) to use this technology to identify novel biomarkers that we can use to guide and monitor the effects of cancer therapies and immune responses (to vaccines or other immunotherapies), and 2) to identify subsets of these nanoparticles and determine their functions in tumor biology, immunobiology, and other aspects of biology.